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Objective To observe the change ofbrain water content,levels of cAMP response element binding protein(CREB)and phosphorylated CREB(p-CREB) in the early stage of traumatic brain injury(TBI) and to investigate the effect of TBI and p-CREB on learning and memory.Methods Fifty-four male adult Wistar rats were randomized into the normal group(18 cases),control group(18 cases) and TBI group(18) according to the random number table method.The TBI model was built according to the modified Feeney method and previous experimental parameters.At 12 h after TBI,Western blot analysis were performed to measure the expressions of hippocampal tissue CREB and p-CREB,the Morris water maze test was used to detect the behavior of rats in each group and the wet-dry method was applied to test brain water content.Results The brain water content at 12 h after TBI in the TBI group was remarkably risen compared with the normal group and control group;the expression levels of hippocampal CREB and p-CREB at 12 h after TBI in the TBI group were significantly decreased compared with the normal group and control group,the latent stage was increased and the frequency searching the accuracy within 2 min was decreased.Conclusion Brain edema is obvious after TBI and the levels of CREB and p-CREB are decreased,which maybe one of the reasons for the impairment of learning and memory function after TBI.
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Objective To observe the protein expression related to cognitive and learning memory function, and to investigate the effect of aquaporin 4 (AQP4) silence on learning and memory function in traumatic brain injury (TBI) rats. Methods Ninety-six healthy adult male Wistar rats were divided into groups according to the random number table. ① Forty-eight rats were divided into sham operation (sham) group, TBI group (by using modified Feeney method), AQP4 RNA interference (RNAi) negative group [TBI+meaningless small interfering RNA (siRNA)-AQP4 liposome solution 10 μL], and AQP4 RNAi group (TBI+siRNA-AQP4 liposome solution 10 μL). In each group, brain tissues of 4 rats were harvested at 1, 6 and 12 hours respectively. The protein expressions of hippocampus AQP4, general control nonderepressible 2 kinase (GCN2), cyclic adenosine monophosphate response element binding protein (CREB) and phosphorylated CREB (p-CREB) were detected by Western Blot. ② In addition, 48 rats were divided into normal control group (control group), sham group, TBI group and AQP4 RNAi group, brain water content were measured in 6 of them after 12 hours of injury, and 6 were used in Morris water maze test. Results ① The protein expressions of hippocampus AQP4 and GCN2 in TBI group were significantly higher than those in sham group, and increased gradually with time with statistical difference at 12 hours (AQP4 protein: 5.03±0.09 vs. 1,GCN2 protein: 4.01±0.13 vs. 1, both 1 < 0.01);the protein expressions of hippocampus CREB and p-CREB were significantly lower than those in sham group, and decreased gradually with time with statistical difference at 12 hours (CREB protein: 0.38±0.03 vs. 1, p-CREB protein:0.38±0.03 vs. 1, both 1 < 0.01). Compared with TBI group, the protein expressions of AQP4 in AQP4 RNAi group was significantly decreased (1 hour: 1.02±0.04 vs. 2.23±0.05, 6 hours: 1.23±0.03 vs. 2.59±0.04, 12 hours: 2.20±0.08 vs. 5.03±0.09, all 1 < 0.01), but there were no significant difference in the expressions of GCN2, CREB or p-CREB. There was no significant difference in the expression of protein between AQP4 RNAi negative group and TBI group.② The brain water content in TBI group was significantly higher than that in control group and sham group [(83.7±0.4)% vs. (76.2±0.2)%, (76.2±0.3)%, both 1 < 0.01]. The brain water content in AQP4 RNAi group [(78.8±0.3)%] was significantly decreased as compared with that in TBI group (1 < 0.01). The latency of Morris water maze test was significantly prolonged in the day 11, 13 and 15 after the injury of the TBI group and AQP4 RNAi group, and the exploration time was significantly shortened. Compared with TBI group, the incubation period of AQP4 RNAi group was significantly shortened at 15 days (s: 60.2±11.1 vs. 62.0±11.5, 1 < 0.05), and the exploration time was significantly prolonged (s: 37.0±8.5 vs. 32.7±9.2, 1 < 0.05). Conclusions The impairment of cognitive and learning memory function in rats after TBI was significantly related to the changes in CREB and GCN2 in cognitive and learning memory function. After RNAi treatment, the cognitive and learning and memory function of rats was not improved obviously, but the brain edema could be alleviated.
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ObjectiveTo investigate the mechanism of dexamethasone (Dex) in inhibiting monocyte adhesion and phagocytose function.Methods Under the stimulation of phorbo1-12-myristate-13-acetate (PMA),U937 monocytes cultured in vitro were treated with Dex and Fasudil respectively.The adhesion rate of U937 monocles to human umbilical vein endothelial cells (HUVECs) and their phagocytic ability of India ink were studied.The protein content and activity of rho-associated coiled-coil protein kinase 1 ( ROCK1 ) as well as the effects of mifepristone and cycloheximide on Dex were determined.ResultsBoth DEX and Fasudil could significantly inhibit the adhesion tate and phagocytosis of U937 cells stimulated by PMA and suppressed the activity of ROCK1.While mifepristone and cycloheximide could not alter these effects of DEX.ConclusionDEX interferes with the adhesion and phagocytosis function of U937 cells by inhibiting ROCKI activity.
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Objective To study the effects of the inhibition of nuclear factor kappa-B ( NF-κB) , on the hepatic heat shock protein 70 (HSP70) expression as well as on the changes of hepatic function and ultrastructure in a rodent model of hemonhageic shock. Method Hemorrhagic shock was produced by inducing bilateral femoral fractures in male Wistar rats. Intraperitoneal injection of pyrrolidine dithiocarbamate(PDTC)was used to inhibit NF-κB activation 1 hour before induction of shock. A total of 66 adult male Wistar rats were randomly divided into 3 groups: control group (Control, n = 6), trauma shock (TS, n = 30), and NF-κB inhibition followed by trauma shock (NF-κB inhibition, n =30). Measurements of hepatic NF-KB and HSP70, hepatic function bio-markers, TNF-α and IL-6 were obtained 0.5, 2, 4, 6, 8 hours after trauma. Histopathological changes in liver tissues were also noted. Hepatic expression of NF-κB was determined by using electrophoretic mobility shift assay, while HSP70 was assayed by western blot and analyzed with computer imaging. Results In rats with trauma shock, both hepatic NF-κB activity and HSP70 expression increased significantly compared to the control group, reaching peaks at 6 hour post injury. Serum alanine transferase (ALT) and total bilirubin (TB) also rose significantly,reaching peaks at 8 hours post trauma. Light microscopy revealed hepatic congestion with infiltration of inflammatory cells into hepatic sinusoid in the TS group at 8 hours. Inhibiting the activity of NF-κB one hour before trauma significantly decreased expression of HSP70 at 6 hours post trauma [16.9±4.4 (NF-κB inhibition) vs. 23.0±1.7 (TS), P ＜ 0.05]. In addition,levels TNF-α and IL-6 in the liver tissue also decreased, and hepatic congestion as well as hepatic cell degeneration were ameliorated, showing minimal inflammatory infiltrates in the hepatic sinusoids. NF-κB inhibition also significantly lowered the levels of ALT and TB at 4 hours post trauma [ALT, 540.8 ±66.2 nmol/L (NF-KB inhibition) vs. 640.6±80.2 nmol/L (TS), P ＜ 0.05; TB,2.3±0.3 mol/L (NF-κB inhibition) vs. 4.7 ±1.1 mol/L (TS), P ＜ 0.05]. Conclusions NF-κB and HSP70 are involved in the pathogenesis of hepatic injury during hemorrhagic shock, and the degree of NF-κB activity and HSP70 expression may be consistent with the extent of hepatocellular damage. Inhibition of NF-κB helps ameliorate liver injury due to trauma shock.
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OBJECTIVE To study the imprinting status of H19 gene in normal villi tissue during the first trimester,and its relation to the invasion of trophoblast. METHODS Using PCR-RFLP methods to examine the imprinting status of H19 gene in 93 cases of normal villi tissue during the first trimester. RESULTS Among 93 cases, heterozygous genotypes were found in 42 cases. And 11 cases of biallelic expression were found among these 42 cases of heterozygous genotypes from 5 to 9 weeks, however no biallelic expression existed from 10 to 12 weeks. CONCLUSIONS During the first trimester, H19 is expressed biallelically at the first 10 weeks. The H19 gene may dynamicly change in the trophoblast, and the dynamic change may have close relationship with the invasion of the trophoblast.
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Objective To detect the expression of hepatocyte cytochrome P450 1A1,2E1 in rat non alcoholic steatosis model. Methods 7 ethoxyresorufin O deethylase (EROD) and benzopyrene hydroxylase (ANH) activity were determined by ultraviolet chromatography. The expression of hepatocyte cytochrome P450 1A1, 2E1 protein in the liver of rats with non alcoholic steatosis induced by high fat diet was detected with immunohistochemistry and Western blot. Cytochrome P450 1A1, 2E1 mRNA were assayed with reverse transcriptase polymerase chain reaction(RT PCR). Results The levels of EROD activity in nonalcoholic steatosis rat at 2, 4, 8, 12 week and normal control group were (325.07?59.68),(345.25?49.28),( 468.95 ?55.28),( 548.68 ?43.25) and (260.42?35.32) nmol?mg -1 ?min -1 respectively. The levels of ANH activity in nonalcoholic steatosis rat at 2, 4, 8, 12 week and normal control group were (635.68 ?65.48), (735.45 ?76.89 ),(887.45?85.65),(956.58?84.47) and (500.25?78.34) nmol?mg -1 ?min -1 respectively. These indicate that the levels of EROD and ANH activity in rats with nonalcoholic steatosis were significantly increased compared with that in control group. In addition, the expression of hepatocyte cytochrome P450 1A1, 2E1 protein and cytochrome P450 1A1, 2E1 mRNA in rats with nonalcoholic steatosis were significantly higher than that in control group. The level of P450 1A1 and 2E1 was increased correspondingly with the degree of nonalcoholic steatosis. Conclusions The induction of hepatocyte cytochrome P4501A1 and 2E1 might participate in the development of nonalcoholic steatosis
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Objective The aim of this study was to investigate the aquaporin-4(AQP4) expression in the ischemic penumbra tissues.Methods Thirty-six Wistar rats were divided into 7 groups randomly, including control group(n=6) and occluded groups(n=30). The occluded groups were studied after the right middle cerebral artery of the rats unilaterally occluded(MCAO) at an interval of 15 min, 30 min, 1 h, 3 h, 6 h and 24 h, respectively(n=5 for each group). The operation process of the control group was the same as the occluded group except occluded MCAO. Then all rats were imaged with T_1WI, T_2WI and diffusion weighted-imaging(DWI). The brain tissue, according to the method by LIU Meili reported, was regarded as the area of the graphic penumbra. The relative apparent diffusion coefficient of the graphic-penumbra (rADC_1) and the center infarction(rADC_2)(ratios between the values of the occluded side and the opposite side) were calculated. The animals were sacrificed and perfused with the mixture solution consisting of TTC at different time intervals. The graphic-penumbra of the biggest layer of the ischemic cerebral tissue which corresponded to the DWI was examined with immunohistochemistry and RT-PCR. Meanwhile, histologic examination was performed at same site of the lesion. Results There were no significant changes on MRI, the relative apparent diffusion coefficient and the expression of the AQP4. The abnormal high intensity was found on DWI at 15 min after MCAO. T_2WI detected the lesion at 1 h after MCAO. The value of the rADC_1 decreased within 24 h after MCAO in ischemic penumbra, especially, it descended quickly within 1 h after MCAO, from(70.4?6.9)% at 15 min to(53.5?10.9)% at 1 h. Whereas, in the infarct tissue, the changes of the rADC_2 had a rule of decrease from(71.5?6.6)% at 15 min to(45.7?10.5)% at 3 h at first time, and then follow an increasing up to(78.7?11.5)% at 24 h after MCAO. The expression of AQP4 increased gradually within 24 h after MCAO, from 0.42?0.05 at 15 min to 1.18?0.12 at 24 h, it showed negative relationship with the rADC_1 in the ischemic penumbra (r= -0.966,P
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AIM: To investigate the functions of GR in the course of hepatic secondary injury after severe multiple injury. METHODS: Rat model was produced by adopting severe thoracic impact injury accompanied with mono-side femur fracture, and glucocorticoid receptor was blocked before severe multiple injury. Hepatic macropathology and alterations under light microscope were examined. Maximal binding volume of glucocorticoid receptor (GR) in hepatic tissue was assayed by radio-ligand binding assay and protein content was assayed by Western blot. RESULTS: Maximal binding volume and protein content of GR were gradually decreased in hepatic tissue after severe multiple injury, obviously lower than that in normal control at 4 h after trauma ( P